Some children naturally engage in high levels of imaginative play (Taylor & Carlson, 1997) and demonstrate developmental benefits associated with their propensity towards pretend-play (e.g., Black, 1992; Carlson, White, & Davis-Unger, 2014; Thibodeau, Gilpin, Brown, & Meyer, 2016). However, these studies have been conducted with samples of convenience and not with children who are at-risk for school readiness deficits, such as those attending Head Start. Recent research suggests that certain abilities (i.e., emotion regulation, appropriate physiological reactivity, executive functions) support the development of school readiness skills, especially among at-risk children raised in low-income environments (Bierman, Nix, Greenberg, Blair, Domitrovich, 2008; Blair & Razza, 2007; Domitrovich, Greenberg, Kusche, & Cortes, 1999; Passolunghi, Vercelloni, & Schadee, 2006; Welsh, Nix, Blair, Bierman, & Nelson, 2011). Although many preschool curricula have been developed to help scaffold school readiness skills in at-risk preschoolers (e.g., Promoting Alternative Thinking Strategies), these curricula are often very costly and require extensive training to implement. Furthermore, the complexity of these programs often places additional burdens on the preschool teachers, leading to poor implementation fidelity (Weiland & Yoshikawa, 2013). In order to improve upon the sustainability of these programs, it is important to identify natural environmental experiences that are implicated in normative development. Consistent with Vygotskian theory, studies suggest that children incur both socio-emotional and cognitive benefits through pretend play (e.g., Black, 1992; Carlson et al., 2014; Thibodeau et al., 2016). Engaging in pretend-play, which typically involves cooperation, shared affect, and support among peers and adults, naturally creates a positive environment that may buffer the observed negative effects of poor emotion regulation/high stress reactivity on cognitive development and school readiness. Unlike the play tested in Tools of the Mind (Bodrova & Leong, 2007), recent research suggests that the pretend play needs to be highly imaginative (fantastical) and child-generated with adult guidance in order for children to reap the most benefits (Russ, 2016; Thibodeau et al., 2016; Weisberg, 2016). The proposed study aims to build upon previous research to identify how pretend-play can serve as a protective factor to minimize deficits in school readiness in an underserved Head Start population in West Alabama. Children's emotion regulation skills, physiological reactivity to stress, executive functions (proximal measure of school readiness), grades and behavior in kindergarten (distal measure of school readiness), and level/style of pretend-play will be assessed to determine if pretend-play moderates the relationship between emotion regulation/physiological stress reactivity and school readiness, both proximally and distally. The findings from this study will inform Head Start researchers, practitioners, and policy makers on how pretend-play can be used as an additional, cost-effective method to facilitate school readiness among Head Start preschool children, and will spur future intervention research.